A centrifuge (a centrifugal separator) is to separate and refine a sample held in a rotor by putting a sample to be separated into a tube or bottle, loading the same to a rotor, accommodating the rotor in a rotor chamber, sealing the rotor chamber and rotating the rotor at high speed. The rotating speed of the rotor is different depending on utilities. A product group having a wide range of rotating speeds, such as a product having a relatively low speed of thousands of revolutions per minute (rpm), which is the maximum rotating speed, and a product having a high speed of about 150,000 revolutions per minute (rpm), which is the maximum rotating speed, is generally supplied. Among of them, a centrifuge having a rotating speed of about 40,000 rpm or higher is provided with a vacuum pump configured to decompress the rotor chamber so as to suppress windage loss (frictional heat) between air in the rotor chamber and the rotor. In general, the vacuum pump consists of an oil rotary vacuum pump functioning as a roughing vacuum pump and an oil diffusion vacuum pump for securing higher vacuum. Further, a cooling device configured to cool the rotor chamber is provided so as to keep the rotor at a preset temperature.
In the centrifuge of the related art, the rotor is detachably mounted to a driving shaft. A user sets a sample container having a sample therein to the detached rotor, covers an opening of the rotor with a cover and then mounts the rotor to the driving shaft in the rotor chamber. In the centrifugal separation operation, it may be necessary to perform a plurality of operations for one specimen at operation conditions having different rotating speeds, for example, in some cases. Further, in some cases, the centrifuge under operation may be stopped to extract or add the sample and the repetition operations may be then performed. A centrifuge is known which has a program operation function capable of automatically switching the operation conditions to perform a step operation. The program operation function is a function of dividing the centrifugal separation operation into a plurality of steps, setting the operation conditions (a rotating speed, time, a temperature and the like) of the centrifuge for each step and automatically operating the set steps in order by a control unit.
JP-A-2008-100124 discloses a technology of implementing the centrifuge program function. According to JP-A-2008-100124, in a case of performing a step operation (a program operation) of continuously operating a centrifuge at operation conditions of a plurality of steps, after inputting step operation conditions by a key input unit, the step operation conditions are displayed on a display unit in a form of a line graph where a rotating speed is displayed on a vertical axis and operating time is displayed on a horizontal axis. However, even when the program operation is performed using the technology of JP-A-2008-100124, there is an inconvenient case when a special centrifugal separation operation is performed. This case is shown in FIG. 12. FIG. 12 illustrates a centrifugal operation including processes of stopping the rotation of the rotor during the entire centrifugal separation operation and adding a sample in a container for specimen. Here, a series of operations of performing a program 01, adding a sample 1, performing a program 02, adding a sample 2 and again performing the program 01 are executed using the technology of JP-A-2008-100124. Here, at time t1, the sample is set to the centrifuge, the program 01 is invoked and an operation is activated by a START button. By a set step function (the program operation function), after STEP 1 (S1) and STEP 2 (S2), the rotor is decelerated and stopped. Here, the user records the operation completion of the program 01 (first) in a notebook and the like. Then, the user presses a vacuum button to stop the vacuum pumps, opens the rotor cover by opening a centrifuge door, supplies the sample into the specimen container, again closes the rotor cover, closes the centrifuge door, invokes the program 02 and pushes the START button at time t4 to start the operation.
Like the program 01, when STEP 3 (S3) and STEP 4 (S4) are operated by the set step function, the rotor is decelerated and stopped. Here, the user records the operation completion of the program 02 (second) in the notebook and the like. Then, the user presses the vacuum button to stop the vacuum pumps, opens the rotor cover by opening the centrifuge door, supplies the sample into the specimen container, closes the rotor cover, closes the centrifuge door, again invokes the program 01 and pushes the START button at time t7 to start the operation. After STEP 1 (S1) and STEP 2 (S2) of the program 01 (second time) are operated, the rotor is decelerated and stopped. Therefore, the user records the operation completion of the program 01 (second) in the notebook and the like, and presses the vacuum button to stop the vacuum pumps, so that the centrifugal separation operation of all processes is over.